1. Field of the Invention
This invention relates to a built-in monitor apparatus such as an electronic game machine and etc., which is adapted to allow a built-in monitor unit having a rectangular picture screen to rotate in a 90-degree arc.
2. Description of the Prior Art
There is a recent trend to enlarge the size of the picture screen of an electronic game machine, for example up to 22-30 inches. On the other hand, there is a demand to minimize the casing for the electronic game machine as small as possible in view of a limited space for installing a number of the electronic game machines in a play room. It is also desirable to array the casings of the electronic game machines as close as possible to each other for effectively utilizing a limited installation space for the electronic game machines. Under these circumstances, it has become increasingly troublesome for an operator to change over the oblong picture screen of an electronic game machine from the vertically elongated state to the horizontally elongated state, and vice versa. Therefore, innovation on this point is now demanded in the art.
Conventionally the change-over of the oblong picture screen of an electronic game machine has been conducted as follows. First, the wirings of a monitor unit and fixing screws are detached from the casing thereof, and then the monitor unit is taken out of the casing of the electronic game machine. Thereafter, the monitor unit is turned to change the posture of the picture screen, i. e. from the vertically elongated state to the horizontally elongated state, and then the monitor unit is returned to the inside of the casing thereof. Finally, the fixings of wirings and fixing screws are conducted.
There has been also proposed as an alternative system a mechanism for rotating the oblong picture screen of an electronic game machine, in which the monitor unit is mounted on a rotatable disc so as to be rotated together with the disc.
However, the former mechanism in which the monitor unit is once taken out of the casing and, after effecting the change-over of the posture of the picture screen, returned to the casing is suffered from problems in that as the monitor unit becomes larger in size and heavier in weight, the more it becomes difficult to conduct the change-over operation.
The latter mechanism of rotating the monitor unit in a 90-degree arc together with the mounting disc is also suffered from problems in that in order to allow the rotation of monitor unit the area of monitor-mounting side of the casing is required to be equal to or larger in size than a square area encircled by four sides, each having a length corresponding to the diagonal line of the picture screen of the monitor unit, thereby inevitably causing an increase in size of the casing.